While a method of supplying power by wire to wireless power receiving apparatuses was traditionally used, a method of supplying power by wireless to wireless power receiving apparatuses without contact has been used in recent years. A wireless power receiving apparatus for receiving power by wireless may be directly driven by the received wireless power, or may charge a battery using the received wireless power and be driven by the charged power.
The Wireless Power Consortium dealing with technologies for wireless power transfer using magnetic induction published a standard document for interoperability in wireless power transfer on Apr. 12, 2010, entitled “System Description Wireless Power Transfer” (Volume 1, Lower Power, Part 1: Interface Definition, Version 1.00 Release Candidate 1). The standard document published by the Wireless Power Consortium discloses a method of transmitting power from one wireless power transfer apparatus to another wireless power transfer apparatus using magnetic induction.